Hemp as an Indicator Species: Mapping the Future of Bio-Based Building

This week on the Hemp Show, we widen the lens. Hemp is more than a crop — it's part of a larger material system that connects farms, forests, manufacturers, builders and cities. Architect and urban researcher Kaja Kühl joins the podcast to explain why she calls hemp and straw "indicator species" — materials that signal the health of a regional building ecosystem. Through her Bio-Based Materials & Construction Resources Map, she has been documenting the farms, processors and builders already working across the Northeast. In this conversation, we explore what it would take to scale regenerative construction from rural landscapes into dense urban markets — and why regional supply chains may matter more than centralized industrial models. We discuss: • Hempcrete as a carbon-storing wall system • Why moisture regulation and indoor air quality may be hemp's most overlooked strengths • Straw panel manufacturing and collaborative scaling models • The advantages — and challenges — of building in a dense Northeastern region • Housing as long-term carbon storage infrastructure Kühl also reflects on building two carbon-zero hemp homes in New York's Hudson Valley and what she learned working alongside early-stage material startups. As federal climate policy shifts, atmospheric carbon does not. If emissions oversight weakens, land-based carbon strategies — including fiber crops like hemp — only grow more consequential. This episode situates hemp inside a broader conversation about how we build, where materials come from and how regional economies can store carbon in the walls around us. News Nuggets Farm Bill / Hemp Language U.S. House Agriculture Committee – Farm, Food and National Security Act of 2026 (Draft Bill Information) National Hemp Association – Industry Response & Policy Updates USDA Hemp Production Program EPA Endangerment Finding EPA 2009 Endangerment Finding (Clean Air Act) Clean Air Act Overview (EPA) Learn More You Are the City – Kaja Kühl's Practice Bio-Based Materials & Construction Resources Map City College of New York – Architecture Columbia University GSAPP Bio-Based Materials Collective https://biobasedcollective.org Thanks to our Sponsor IND HEMP